/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina.startup;

import org.apache.tomcat.util.digester.Digester;
import org.apache.tomcat.util.digester.RuleSetBase;

/**
 * <p><strong>RuleSet</strong> for processing the contents of a Realm definition
 * element.  This <code>RuleSet</code> supports Realms such as the
 * <code>CombinedRealm</code> that used nested Realms.</p>
 */
public class RealmRuleSet extends RuleSetBase {

	private static final int MAX_NESTED_REALM_LEVELS = Integer.getInteger(
			"org.apache.catalina.startup.RealmRuleSet.MAX_NESTED_REALM_LEVELS",
			3).intValue();

	// ----------------------------------------------------- Instance Variables

	/**
	 * The matching pattern prefix to use for recognizing our elements.
	 */
	protected String prefix = null;


	// ------------------------------------------------------------ Constructor

	/**
	 * Construct an instance of this <code>RuleSet</code> with the default
	 * matching pattern prefix.
	 */
	public RealmRuleSet() {

		this("");

	}

	/**
	 * Construct an instance of this <code>RuleSet</code> with the specified
	 * matching pattern prefix.
	 *
	 * @param prefix Prefix for matching pattern rules (including the
	 *               trailing slash character)
	 */
	public RealmRuleSet(String prefix) {

		super();
		this.namespaceURI = null;
		this.prefix = prefix;

	}


	// --------------------------------------------------------- Public Methods

	/**
	 * <p>Add the set of Rule instances defined in this RuleSet to the
	 * specified <code>Digester</code> instance, associating them with
	 * our namespace URI (if any).  This method should only be called
	 * by a Digester instance.</p>
	 *
	 * @param digester Digester instance to which the new Rule instances
	 *                 should be added.
	 */
	@Override
	public void addRuleInstances(Digester digester) {
		StringBuilder pattern = new StringBuilder(prefix);
		for (int i = 0; i < MAX_NESTED_REALM_LEVELS; i++) {
			if (i > 0) {
				pattern.append('/');
			}
			pattern.append("Realm");
			addRuleInstances(digester, pattern.toString(), i == 0 ? "setRealm" : "addRealm");
		}
	}

	private void addRuleInstances(Digester digester, String pattern, String methodName) {
		digester.addObjectCreate(pattern, null /* MUST be specified in the element */,
				"className");
		digester.addSetProperties(pattern);
		digester.addSetNext(pattern, methodName, "org.apache.catalina.Realm");
	}
}
